JP2013007317A5

JP2013007317A5 -

Info

Publication number: JP2013007317A5
Application number: JP2011140152A
Authority: JP
Filing date: 2011-06-24
Publication date: 2014-07-31

Description

本発明の一つの特徴によれば、エンジンと、エンジンに供給される燃料を貯蔵する燃料タンクと、エンジンから排出される排気音を抑制するマフラーを有し、エンジンの駆動軸方向、排気口の開口方向、ピストンの動作方向がそれぞれ略直交するよう構成されたエンジン作業機であって、マフラーは、内部の膨張室の一つがエンジンの排気口に連結されるようにエンジンの排気口に遮熱板を介して締結され、締結位置においてピストンの移動方向と平行な締結平面よりもエンジン側に延在する突出部を有し、突出部がエンジンのピストンの移動方向において点火プラグから遠い側の端部近傍に配置される。遮熱板は、マフラーの締結平面と略平行に延びるとともに、点火プラグから遠い側において、エンジンのクランクケースの外周に沿って屈曲し、クランクケースと突出部との間に配置される。 According to one aspect of the present invention, an engine, a fuel tank that stores fuel supplied to the engine, and a muffler that suppresses exhaust noise discharged from the engine are provided. opening direction, the direction of movement of the piston is an engine working machine configured orthogonal substantially respectively, muffler, shielding the exhaust port of the engine as one internal expansion chamber is connected to an exhaust port of the engine It has a protrusion that is fastened via a hot plate and extends to the engine side from the fastening plane parallel to the moving direction of the piston at the fastening position, and the protruding part is located on the side farther from the spark plug in the moving direction of the piston of the engine. end Ru is arranged in the vicinity. The heat shield extends substantially parallel to the muffler fastening plane, bends along the outer periphery of the crankcase of the engine on the side far from the spark plug, and is disposed between the crankcase and the protrusion .

請求項１によれば、マフラーの一部にエンジン側に延在する突出部を設け、燃料タンクをエンジンのクランクケースの下部であってマフラーの突出部の側方にオフセットして設けるようにしたので、駆動軸の両端の各部に影響を与えることが少なく、点火プラグの交換作業等の妨げとなることが少なく、排気口の開口方向へのエンジン全長を大きくすることなくマフラー容積を効果的に増加させることができる。従って、コンパクトな構成で背圧低減および出力向上をし易くなり、更に、排気音の低減効果を得ることができる。また、遮熱板はクランクケースと突出部との間に配置されるので、マフラーの熱がエンジンの冷却へ影響することを低減できる。
According to the first aspect of the present invention, the projecting portion extending to the engine side is provided in a part of the muffler, and the fuel tank is provided at the lower portion of the crankcase of the engine and offset to the side of the projecting portion of the muffler. Therefore, it hardly affects each part at both ends of the drive shaft, hardly disturbs the replacement work of the spark plug, etc., and effectively increases the muffler volume without increasing the total engine length in the opening direction of the exhaust port. Can be increased. Therefore, it is easy to reduce the back pressure and improve the output with a compact configuration, and further, it is possible to obtain the effect of reducing the exhaust noise. Further, since the heat shield plate is disposed between the crankcase and the protrusion, it is possible to reduce the influence of the heat of the muffler on the cooling of the engine.

Claims

An engine, a fuel tank that stores fuel supplied to the engine, and a muffler that suppresses exhaust noise discharged from the engine; a driving shaft direction of the engine, an opening direction of an exhaust port, and an operating direction of a piston Are engine working machines configured to be substantially orthogonal to each other,
The muffler
One internal expansion chamber is fastened through the heat shield plate to the exhaust port of the engine to be connected to an exhaust port of the engine,
It has a protrusion that extends to the engine side with respect to the fastening plane parallel to the moving direction of the piston at the fastening position, and the protruding part is disposed near the end portion on the side far from the spark plug in the moving direction of the piston of the engine. ,
The heat shield plate extends substantially parallel to a fastening plane of the muffler and bends along the outer periphery of the crankcase of the engine on the side far from the spark plug, between the crankcase and the protrusion. An engine working machine characterized by being arranged .

The volume of the muffler is at least 17 times the displacement of the engine, and the opening area of the tail pipe formed at the exhaust port of the muffler is 0.3 to 0.8 times the displacement. The engine working machine according to claim 1, wherein:

The engine is arranged such that the piston reciprocates in the vertical direction,
The cross section of the exhaust port of the engine is positioned so as to be substantially vertical,
3. The engine work machine according to claim 1, wherein a dimension of the muffler is a vertically long shape such that thickness direction <lateral direction <vertical direction. 4.

The engine working machine according to claim 3, wherein a ratio of a longitudinal direction / a lateral direction of a dimension of the muffler is 1.5 or more.

The muffler is fastened to the engine by fastening means, in the muffler side and the exhaust port facing the muffler side of the side away from the engine, the rigidity of the muffler side at a position spaced in the direction of movement of the piston from said fastening means The engine working machine according to claim 4, wherein means for increasing the pressure is arranged.

The means for increasing the rigidity is a screw and a tube passing through the screw,
The tube engine working machine according to claim 5, characterized in that it is fixed to the muffler side facing the far side of the muffler side and front Sharing, ABS air outlet from the engine.

The interior of the muffler, front has a first expansion chamber communicating with Sharing, ABS air inlet, an exhaust gas second expansion chamber having an outlet for discharging to the atmosphere,
Providing a third expansion chamber connecting the first expansion chamber and the second expansion chamber;
The engine working machine according to claim 6, wherein a catalyst for purifying an exhaust gas component is disposed in the third expansion chamber.

The engine working machine according to claim 7, wherein the third expansion chamber is disposed so as to include an internal space of the protruding portion.